在以次亚磷酸钠为还原剂、硼酸为缓冲剂和柠檬酸钠为络合剂的碱性介质中,化学沉积钴 铁 磷合金和钴 磷合金.研究了沉积工艺,如pH值和主盐CoSO4/FeSO4的摩尔比对沉积速率的影响.发现镀液中的硫酸亚铁对钴 铁 磷合金沉积有阻碍作用,以致其沉积速率比钴 磷的低.电化学极化实验表明,硫酸亚铁既影响阳极过程又影响阴极过程,它降低了两者的极化电流和极化电势.电化学实验结果与沉积速度测量结果基本相符.
关键词：
化学沉积; 合金; 钴; 铁; 电化学极化
Electroless deposition of Co-P alloy and Co-Fe-P alloy from an alkaline bath, containing sodium hypophosphite as a reducer, boric acid as a buffer agent and sodium citrate as a complexing agent, was investigated respectively. The effects of process parameters, such as pH of solution and metallic salt mole ratio of CoSO_(4)/FeSO_(4), on the plating rate were examined. It was found that the presence of ferrous sulfate in the bath has an inhibitory effect on the alloy deposition. As a consequence, the plating rate of Co-Fe-P is lower than that of Co-P. The electrochemical polarization measurements have been carried out to examine the effect of ferrous sulphate on the cathodic or the (anodic) polarization process. The ferrous sulphate affects both the cathodic and anodic polarization processes, which reduces the deposition current and potential. The results of the electrochemical polarization experiments agree well with those of electroless deposition rate measurements.
[1] HommaT,KitaY,OsakaT.Microstructuralstudyonthefunctionallygradedmagneticthinfilmspreparedbyelectrolessdeposition[J].J.Electrochem.Soc.,2000,147:160.
[2] FarrJPG,AbbasNoshaniA.SomepropertiesofelectrolessNi P,Co P,andNi Co Pdeposits[J].TransIMF.,1996,74:221.
[3] JuddgeJS,MorrisonJR,SpeliotisDE,etal.MagneticpropertiesandcorrosionbehaviorofthinelectrolessCo Pdeposits[J].J.Electrochem.Soc.,1965,681.
[4] CortijoRO,SchlesingerM.StructuralstudiesofelectrolessthinCo Pfilms[J].J.Electrochem.Soc.,1984,131:2800.
[5] TarozaiteR,KurtinaitieneM,DziuveA,etal.Composition,microstructureandmagneticpropertiesofelectrolessplatedthinCo Pfilms[J].Surf.＆Coat.Technol.,1999,115:57.
[6] BouananiM,CherkaouiF,CherkaouiM,etal.Ni Zn Palloydepositionfromsulfateboth:inhibitoryeffectofzinc[J].J.Appl.Electrochem.,1999,29:1171.
[7] WangSL,WuHH.TheelectrolessplatingNi Fe Palloyanditsvoltammetricbehavior[J].Electrochemistry,2003,9(3):327.
[8] OhnoI.Electrochemistryofelectrolessplating[J].MaterialsSci.Eng.,1991,A146:33.
[9] PaunovicM.Electrochemicalaspectsofelectrolessdepositionofmetals[J].Plating,1968,Nov.:1161.
